I love using prime lenses. When given the choice, I will always choose carrying a bag of prime lenses than 1 or 2 super zooms. In an article for In-My-Bag.com from a while ago, I wrote about the kit I take with me usually with few prime lenses. My equipment have shifted around a bit, but I still focus on owning less and having them do more.
For portraits and general head shots, I find using the 85mm to be very pleasurable. It gives me no distortion and offers me a good working distance from the subject, not too close and not too far away. The natural thought for us working photographers is to get the fastest version (most expensive) of the lens. For the 85mm, the price and the weight difference was significant. I can buy 3 1.8G for the price of 1 1.4G, and it is much heavier than the 1.8G counterpart.
So a shoutout to the humble Nikon 85mm 1.8G. The lens is incredibly sharp. Is it as sharp as the 1.4? I don't know, but I find it to be sharp enough for me. And really, the sharper the lens is, the more retouching there is... To give you an idea of how sharp the lens is, below is an example shot at f/4(!).
The lens is small and relatively light for 85mm. It feels hefty but not heavy and it balances very well on the Nikon D810. When shooting portraits, I find using the lens to be very pleasurable and easily controllable without having to worry at all about the image quality. For Nikon photographers out there, I highly recommend the 85mm 1.8G. It is light and affordable and has really high cost/performance ratio.
I was even confident enough to take the lens to many celebrity shoots, photographing Tilda Swinton, Kate Upton and more with it.